For my watercolor portraits I use a layering technique, applying colors separately. This process allows me to focus on edge quality and tone, while keeping the colors fresh and luminous.  I sometimes add other media , like watercolor crayons, pastel or gouache.

When I am done with the layering process, I usually correct the colors by addition (adding new colors, usually secondaries and Tertiary colors : purple, oranges, greens and browns) and by subtraction (scrubbing the paper with water and an old stiff brush).

Here are the steps I took:

Layering process for watercolor portraits painting : Face painting

This is my drawing. I used Arches cold press watercolor paper 140 lb and worked from a picture.

This is the first layer. I used only Yellow ocher (Da Vinci). I masked the face painting area because I will paint it at the end with pure colors

This is the second layer, I used a Pinkish warm red (Alizarin crimson, Da Vinci) for most of the parts and some more orange-red (Permanent red light) On places I wanted a more orange color.

On the third layers I used also two different blues, a warmer blue on most of the shades of the face (Ultramarine Rembrandt) and a colder blue on the areas where the light was cold on the face(Prussian blue, Da Vinci)

In the last stage, I adjust colors where I need to do it, I scrub and wash away some paint where I need more light on the face, I soften some edges, and then paint the face painting.